LOANS - Unpaid Principal Balances by Delinquency Status (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2025	Dec. 31, 2024
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	$ 13,192,117	$ 13,192,117	$ 11,183,408
Nonaccrual Loans	254,498	254,498	168,915
Total Loans	15,721,111	15,721,111	13,609,172
Nonaccrual loans with no associated allowance	39,500	39,500	41,500
Interest received on nonaccrual loans	1,900	5,000	4,900
Total Agricultural Finance loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans	241,782	241,782	168,915
Total Loans	9,572,831	9,572,831	8,834,689
Farm & Ranch
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	8,120,433	8,120,433	7,453,015
Nonaccrual Loans	188,200	188,200	123,546
Total Loans	8,120,433	8,120,433	7,453,015
Corporate AgFinance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	1,452,398	1,452,398	1,381,674
Nonaccrual Loans	53,582	53,582	45,369
Total Loans	1,452,398	1,452,398	1,381,674
Infrastructure Finance loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	6,148,280	6,148,280	4,774,483
Nonaccrual Loans	12,716	12,716	0
Total Loans	6,148,280	6,148,280	4,774,483
Financial Asset, Not Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	15,407,773	15,407,773	13,410,152
Financial Asset, Not Past Due [Member] | Total Agricultural Finance loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	9,272,209	9,272,209	8,635,669
Financial Asset, Not Past Due [Member] | Farm & Ranch
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	7,873,393	7,873,393	7,299,364
Financial Asset, Not Past Due [Member] | Corporate AgFinance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	1,398,816	1,398,816	1,336,305
Financial Asset, Not Past Due [Member] | Infrastructure Finance loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	6,135,564	6,135,564	4,774,483
Financial Asset, Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	58,840	58,840	30,105
Financial Asset, Past Due [Member] | Total Agricultural Finance loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	58,840	58,840	30,105
Financial Asset, Past Due [Member] | Farm & Ranch
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	58,840	58,840	30,105
Financial Asset, Past Due [Member] | Corporate AgFinance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	0	0	0
Financial Asset, Past Due [Member] | Infrastructure Finance loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	0	0	0
30-59 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	34,291	34,291	16,478
30-59 Days | Total Agricultural Finance loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	34,291	34,291	16,478
30-59 Days | Farm & Ranch
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	34,291	34,291	16,478
30-59 Days | Corporate AgFinance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	0	0	0
30-59 Days | Infrastructure Finance loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	0	0	0
60-89 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	10,809	10,809	7,268
60-89 Days | Total Agricultural Finance loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	10,809	10,809	7,268
60-89 Days | Farm & Ranch
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	10,809	10,809	7,268
60-89 Days | Corporate AgFinance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	0	0	0
60-89 Days | Infrastructure Finance loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	0	0	0
90 Days and Greater
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	13,740	13,740	6,359
90 Days and Greater | Total Agricultural Finance loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	13,740	13,740	6,359
90 Days and Greater | Farm & Ranch
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	13,740	13,740	6,359
90 Days and Greater | Corporate AgFinance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	0	0	0
90 Days and Greater | Infrastructure Finance loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	$ 0	$ 0	$ 0